• The colors show brain areas that were active during a memory task in a 20-year old who did not use alcohol. Compare this with the brain of a 20-year old who had been drinking heavily for 5 years, which shows far less activation and resulted in worse performance on the same memory task.
  • Drugs have a lasting impact on the brain, even after a person has stopped using. The brain of a former ecstasy user shows far less activation than a person who has never used ecstasy.
  • The hippocampus, a brain structure critical for learning and memory, is especially sensitive to damage from alcohol and marijuana.
  • The hippocampus tends to be smaller in heavy drinking adolescents compared to teens who did not drink.
  • At age 13, before anyone started using marijuana, everyone in the study had about the same IQ.
  • 25 years later, those who smoked marijuana heavily for 3 or more years had a big drop in their IQ.
  • Those who started before age 18 had a bigger drop than those who started after age 18.
  • Drugs and alcohol have both immediate and long-term neurotoxic effects on the developing brain structure and function.